#include <bits/stdc++.h>
using namespace std;
#define pb push_back
#define mp make_pair
#define f1 first
#define s2 second
#define fastio ios :: sync_with_stdio(0); cin.tie(0); cout.tie(0);
#define debug(x) cerr << "[" << #x << "]: " << x << "\n";
using ll = long long;
using ld = long double;
using ii = pair<int, int>;
using pl = pair<ll, ll>;
constexpr ld PI = 4*atan((ld)1);
constexpr int MAX = 2069;
int n, p, q;
int ar[MAX], small[MAX], big[MAX];
int dp[MAX][MAX];
inline bool check(int w)
{
for (int i = 1; i <= n; ++i)
{
small[i] = big[i] = i;
while (small[i] < n && ar[small[i] + 1] - ar[i] + 1 <= w) small[i]++;
while (big[i] < n && ar[big[i] + 1] - ar[i] + 1 <= 2*w) big[i]++;
}
memset(dp, 0, sizeof(dp));
for (int i = 0; i <= min(n, p); ++i)
{
for (int j = 0; j <= min(n, q); ++j)
{
if (i) dp[i][j] = max(dp[i][j], small[dp[i-1][j] + 1]);
if (j) dp[i][j] = max(dp[i][j], big[dp[i][j-1] + 1]);
if (dp[i][j] == n)
return true;
}
}
return false;
}
int main()
{
fastio;
cin >> n >> p >> q;
for (int i = 1; i <= n; ++i)
cin >> ar[i];
sort(ar+1, ar+n+1);
int l = 1, r = 1e9;
while (l < r)
{
int mid = (l + r) >> 1;
if (check(mid)) r = mid;
else l = mid + 1;
}
cout << l << '\n';
return 0;
}
